That is where some of the most challenging images come from... especially with white 4pt type against highly patterned backgrounds. However, frankly with a jeweler's loupe even on the most difficult images, I can't tell the difference flickering between compressed and uncompressed at 4:1. If you think about it, H264 is 100:1 compression (PNG 20:1) so it's not surprising that human eye visibility (especially at 10bit HDR and 8k) is excellent.
For a quantitative estimate, PSNR is ~40dB even on fairly extreme images, which means less that those +/-1 code for 8bit sRGB. I'd expect even better from 10bit and natural images to be >45dB.